CVE-2026-56864Ignore unrelated, unauthenticated hashes in Lookup in golang.org/x/mod/sumdb
Updated under an hour ago ()
Does this affect you?
It affects Go toolchain cmd/go and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
A malicious GOSUMDB was capable of serving arbitrary module content not contained within the transparency log. This attack allows for a coordinating GOPROXY and GOSUMDB to serve a client malicious module content that cannot be detected by evaluating the transparency log. In order to determine if you have been affected: rm -r go.sum go.work.sum vendor/ && go mod tidy
- CVSS
- 7.5 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weakness (CWE)
- CWE-347
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Go
- NVD analysis
- Awaiting Analysis
- Record last updated
- Aug 14, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Go toolchain cmd/go go_toolchain:cmd_go (from the name) | before 1.25.13; from 1.26.0-0 before 1.26.6; 1.27.0-0 builds before 1.27.0-rc.3 | CNA record |
golang.org/x/mod golang.org/x/mod/sumdb golang.org_x_mod:sumdb (from the name) | before 0.40.0 | CNA record |
References
- https://go.dev/issue/80745
- https://groups.google.com/g/golang-announce/c/94pEornpRlI
- https://go.dev/cl/815000
- https://go.dev/cl/815020
- https://pkg.go.dev/vuln/GO-2026-6180
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.